If the structure of the chain is not compromised (not worn too badly), you can just soak it in WD40, dry it off and blow out the links with compressed air. You might want to use a hand held wire brush to loosen more stubborn oxidation. Repeat a couple of times in an effort to do your best to flush out debris.

Now, clean the chain one more time with WD40 and blow dry. Apply your preferred chain lube. I use Prolink. After trying several different brands and formulas, Prolink has proved to work the best and with least maintenance hassle. Soak every single pivot point. Every one!

Dry the exterior of the chain off and off you go. I have done this many times and with great success. But the chain must not be worn.

Hope this is a help.